Such a heat transfer medium assembly unit is known, for example, from DE 101 44 174 C1. The heat exchanger arrangement, in conjunction with which this prior-art heat transfer medium assembly unit can be used, comprises, associated with each connecting branch to be used, i.e., associated with a connecting branch used to feed the heat transfer medium and associated with a connecting branch used to remove the heat transfer medium, a connection opening each, into which an end section of a respective connecting branch can be inserted. The interaction of the connecting branches with the heat exchanger body is such that a preassembled state is established between the connecting branch, on the one hand, and the heat exchanger body, on the other hand, either by generating a press fit between a conical end section of a connecting branch and a correspondingly conically shaped connection opening or by a positive-locking meshing formation, which prevents the rotation of a connecting branch in relation to the heat exchanger body. The connecting branches positioned in the preassembled state in relation to the heat exchanger body are fixed at the heat exchanger body by a connecting branch holding-down clamp designed in the form of a plate-like component such that they can neither by rotated nor moved out of the associated connection openings.
Especially when a plate-like connecting branch holding-down clamp is used, this connecting branch holding-down clamp can be arranged on the heat exchanger body already assembled with the connecting branch in a complicated manner because of the bent shape of the connecting branches and because access to this assembly area is thus made difficult.